Nokia Lumia 710 / 800 / 800C TP BOOT REPAIR Solution Here

The solution described below is for phones with "un-alligned" or corrupted AMSS + ADSP Region caused by improper custom firmware flashing or by other means of data corruption.

Here is sample logs showing the error during Normal USB Flashing:
================================================== ======
Sending OSBL Certificate HASH: C72DBA3ABED42215584093FA9DE247381D6062B4
Certificate Size: 452 Bytes

ERROR: Data Rejected at SEQ 0x3
Status : WRITE OSBL CERTIFICATE FAILED
==============================================
STEP 1:In order to fix this problem, you first need to write QUALCOMM OSBL to your phone via TP Method.
Select Correct Phone Type and make sure M.B.R. + SEC_BOOT + OSBL QCOM is selected as well. Then click REPAIR BOOT!!!

STEP 2:Remove USB Cable and press and hold POWER BUTTON for 18 Seconds. Then press and hold VOLUME UP Button while connecting the USB Cable to the phone.
*** Your Phone should now be detected as a New HDD Device and Windows will ask you to FORMAT IT... Of course

DO NOT FORMAT

STEP 3:
Download the proper RAW BOOT Files for your phone.

Lumia 710 RM-803 and RM-809
Lumia 800 RM-801 and RM-819
Lumia 800C RM-802STEP 4:
Go to eMMC Direct tab in ATF Software and click "Scan Partitions". If your phone is NOT DETECTED, go back to STEP 2. Repeat Step 2 until your phone is DETECTED Properly.

After ATF Software successfully Lists the Partitions Found on the Phone, click "Backup Phone Data" so you will save your IMEI, Simlocks and other important data safely.

STEP 5:
Now Let us write Boot Files which you downloaded from Step 3.
Extract the RAR file and then write the 3 RAW Boot Files 1 by 1:
5a. dbl_RM-XXX.bin <--- Write this to 0x4D - DBL Partition
5b. osbl_nokia_RM-XXX.bin <--- Write this to 0x46 - OSBL Partition
5c. amss_adsp_RM-XXX.bin <--- Write this to 0x0C - AMSS_ADSP Partition

5a - DBL

5b - OSBL_NOKIA


5c - AMSS_ADSP



STEP 6:Click "SP UNLOCK" if you want to unlock your phone after fixing the BOOTS.

STEP 7: 
Flash the WP_OS partition using your regular ESCO Flash Files. This will have the same effect as you will flash the phone via USB... but via eMMC Direct, it is faster and does not care if your KEYSTORE is damaged or erased.

Write Flash file to 0x48 WP_OS Partition.

Flash File should be the BOOT file and should be more than 300 MB in size.

It looks like this:

RMxxx_11111_prod_111_11_boot.esco <--- 300+ MB

*** WARNING: Everytime you flash your phone with another firmware, you will always RESET the SP Lock status and RESET the SP Lock Counters. To avoid your phone from getting RE-LOCKED, always make sure to UN-CHECK the"XXXXXXX_prod_generic_amss.esco" flash file before you click the FLASH Button. By Skipping this file, you can always re-enter "00000000" to unlock your phone again after flashing.